Bah Humbug!
You need to realise that Christmas is different down here, but not necessarily worse or better, just different. When in another country, another hemisphere even, adapt, survive and enjoy.
I worried about how I would cope, but got myself friendly with a local family. They invited me out to their family Christmas (Christmas Eve) made me thouroughly at home, and had one whale of a time.
Christmas Day was just a succession of expat parties all the way through until midnight (had to rush off to a milonga then).
Tango friends then threw another party Boxing day, ended up in another milonga, hey ho.
Go out meet people, go to the Plazas Christmas eve and New years eve, and see the mad fireworks, get drunk if you must. Most of all, do not sit alone and mope. Buenos Aires goes mad over the festivities, if you do not enjoy it, the fault is yours, not Buenos Aires.